LOANS AND ALLOWANCE FOR LOAN LOSSES (Summary of Aging of the Loan Portfolio by Segment) (Details) - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017
Financing Receivable, Recorded Investment, Past Due [Line Items]
Greater than 90 Days and still Accruing	$ 6,921	$ 3,532
Total Loans	9,290,259	7,141,552
Nonaccrual	25,662	21,743
Current	9,124,900	7,053,016
Purchased Impaired
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Loans	101,524	39,021
Current	86,007	35,418
30 to 59 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	21,030	16,873
60 to 89 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	10,222	7,367
Construction and Land Development
Financing Receivable, Recorded Investment, Past Due [Line Items]
Greater than 90 Days and still Accruing	144	1,340
Total Loans	1,250,448	948,791
Nonaccrual	6,485	5,610
Current	1,237,696	936,857
Construction and Land Development | Purchased Impaired
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Loans	5,183	2,838
Current	3,860	2,773
Construction and Land Development | 30 to 59 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	648	1,248
Construction and Land Development | 60 to 89 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	292	898
Commercial Real Estate - Owner Occupied
Financing Receivable, Recorded Investment, Past Due [Line Items]
Greater than 90 Days and still Accruing	2,512	0
Total Loans	1,293,791	943,933
Nonaccrual	2,845	2,708
Current	1,256,120	925,910
Commercial Real Estate - Owner Occupied | Purchased Impaired
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Loans	26,720	14,790
Current	22,523	13,931
Commercial Real Estate - Owner Occupied | 30 to 59 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	3,775	444
Commercial Real Estate - Owner Occupied | 60 to 89 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	1,819	81
Commercial Real Estate - Non-Owner Occupied
Financing Receivable, Recorded Investment, Past Due [Line Items]
Greater than 90 Days and still Accruing	0	194
Total Loans	2,318,589	1,713,659
Nonaccrual	3,068	2,992
Current	2,290,797	1,703,592
Commercial Real Estate - Non-Owner Occupied | Purchased Impaired
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Loans	24,680	6,610
Current	22,387	6,189
Commercial Real Estate - Non-Owner Occupied | 30 to 59 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	44	187
Commercial Real Estate - Non-Owner Occupied | 60 to 89 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	0	84
Multifamily Real Estate
Financing Receivable, Recorded Investment, Past Due [Line Items]
Greater than 90 Days and still Accruing	0	0
Total Loans	541,730	357,079
Nonaccrual	0	0
Current	541,560	356,999
Multifamily Real Estate | Purchased Impaired
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Loans	84	80
Current	84	80
Multifamily Real Estate | 30 to 59 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	86	0
Multifamily Real Estate | 60 to 89 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	0	0
Commercial & Industrial
Financing Receivable, Recorded Investment, Past Due [Line Items]
Greater than 90 Days and still Accruing	100	214
Total Loans	1,093,771	612,023
Nonaccrual	1,387	316
Current	1,086,945	609,829
Commercial & Industrial | Purchased Impaired
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Loans	1,851	408
Current	1,315	408
Commercial & Industrial | 30 to 59 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	1,921	1,147
Commercial & Industrial | 60 to 89 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	1,567	109
Residential 1-4 Family - Commercial
Financing Receivable, Recorded Investment, Past Due [Line Items]
Greater than 90 Days and still Accruing	132	579
Total Loans	723,945	612,395
Nonaccrual	1,998	1,085
Current	701,618	598,935
Residential 1-4 Family - Commercial | Purchased Impaired
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Loans	17,227	9,414
Current	14,890	8,630
Residential 1-4 Family - Commercial | 30 to 59 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	2,216	1,682
Residential 1-4 Family - Commercial | 60 to 89 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	754	700
Residential 1-4 Family - Mortgage
Financing Receivable, Recorded Investment, Past Due [Line Items]
Greater than 90 Days and still Accruing	2,669	546
Total Loans	607,155	485,690
Nonaccrual	7,552	6,269
Current	571,018	468,763
Residential 1-4 Family - Mortgage | Purchased Impaired
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Loans	18,002	3,733
Current	14,256	2,764
Residential 1-4 Family - Mortgage | 30 to 59 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	4,926	3,838
Residential 1-4 Family - Mortgage | 60 to 89 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	2,988	2,541
Auto
Financing Receivable, Recorded Investment, Past Due [Line Items]
Greater than 90 Days and still Accruing	121	40
Total Loans	296,706	282,474
Nonaccrual	463	413
Current	293,505	278,295
Auto | Purchased Impaired
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Loans	11	0
Current	11
Auto | 30 to 59 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	2,187	3,541
Auto | 60 to 89 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	419	185
HELOC
Financing Receivable, Recorded Investment, Past Due [Line Items]
Greater than 90 Days and still Accruing	570	217
Total Loans	626,916	537,521
Nonaccrual	1,669	2,075
Current	613,660	531,180
HELOC | Purchased Impaired
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Loans	6,890	950
Current	5,826	445
HELOC | 30 to 59 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	2,505	2,382
HELOC | 60 to 89 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	1,622	717
Consumer and all other
Financing Receivable, Recorded Investment, Past Due [Line Items]
Greater than 90 Days and still Accruing	673	402
Total Loans	537,208	647,987
Nonaccrual	195	275
Current	531,981	642,656
Consumer and all other | Purchased Impaired
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Loans	876	198
Current	855	198
Consumer and all other | 30 to 59 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	2,722	2,404
Consumer and all other | 60 to 89 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	$ 761	$ 2,052